1. Field of the Invention
The present invention relates to the termination of telephone calls in a telephone network that provides a privacy screening service to its subscribers.
2. Background of the Invention
A privacy screening service is a service that allows a subscriber to the privacy screening service to screen incoming calls. The privacy screening service provides information to the called party (in this case, the subscriber to the privacy screening service) that allows the subscriber to make an informed decision as whether or not to answer the call. For example, a subscriber may use the privacy screening service to block all unidentified calls from going through. Private telephone numbers are telephone numbers that block services such as xe2x80x9ccaller IDxe2x80x9d that would otherwise identify the caller to the called party. In telephone systems that offer private numbers and a privacy screening service to its customers, calls from a private number to a subscriber with the privacy screening service cannot be completed automatically, unless the caller authorizes the system to override the privacy of his number.
FIG. 1 is a schematic diagram showing the basic architecture of an Advanced Intelligent Network telephone system. The Advanced Intelligent Network System is described in U.S. Pat. No. 5,701,301 and U.S. Pat. No. 5,838,774, which are hereby incorporated by reference. FIG. 1 shows the caller""s telephone 101 which is connected via the calling party""s voice line 102a to its Service Switching Point (SSP) 103. SSP 103 is connected via voice trunk 102b to a second SSP (SSP 104). SSP 104 is the SSP that services the called party""s telephone 105. In this example, the called party is a subscriber who has subscribed to the privacy screening service. (The called party will also be referred to as the xe2x80x9csubscriberxe2x80x9d as well as the xe2x80x9ccalled partyxe2x80x9d herein.) FIG. 1 also shows a Signaling Transfer Point (STP) 106 which services a Service Control Point (SCP) 107 and a third SSP (SSP 108) which services a Service Node (SN) 109. SCP 107 has a database 107a that contains subscriber information.
STP 106 is a signaling hub that routes packets of data over the common channel signaling network. Common channeling signaling networks are data communications networks laid over the system""s switching network that carry data and control messages to and from and among the SSPs, STPs, and SCPs in the network. Signaling System 7 (SS7) is the protocol that runs over common channel signaling networks. A common channel signaling network using the Signaling System 7 protocol is often referred to as an SS7 network. The SS7 network carries data and control messages to the SSPs in the telephone network. SCPs are powerful fault-tolerant computers, e.g., ATandT Star Server FT Model 3200 or ATandT Star Server FT Model 3300 computers (these and more current computers such as the Advantage P200 and Advantage 4P200 models are presently available from Lucent Technologies). SCPs are xe2x80x9cintelligence centersxe2x80x9d with access to applications databases that enable the network to deliver advanced services such as caller ID, privacy screening and call forwarding. The SCPs also execute service package applications (SPAs) that deliver the advanced services. SNs are physically generally similar to SCPs, but include voice and Dual Tone Multi-Frequency (DTMF) signal recognition circuits, voice synthesizers, and voice recognition and digit collection capabilities. The operators of the telephone network can program their SNs to manage data, to respond to calls and to route calls as specified by the telephone network, and to collect digits from a caller or subscriber. The SN""s voice circuits can also be programmed to provide a voice response (e.g., to play pre-selected announcements) to callers and to perform voice recognition. SNs can also be programmed to respond to input from the callers by, e.g., further routing the call.
As shown in FIG. 1, STP 106 controls communications between SSPs 103, 104 arid 108 and SCP 107. The SSPs are connected to the caller""s and the subscriber""s telephones and to each other via voice lines 102a and 102c and via voice trunks 102b and 102d. The SSPs communicate with STP 106 and SCP 107 via SS7 data links 110a, 110b, 110c and 110d. SN 109 is connected to SSP 108 by an Integrated Service Digital Network (ISDN) Basic Rate Interface (BRI) line 111.
When the caller places a call to the subscriber, the call is routed by SSP 103 to SSP 104. FIG. 1a shows a prior art system in which call 1 is routed from the caller to SSP 103 and then to SSP 104. Because the subscriber has subscribed to the privacy screening service, that call (like all calls to that subscriber""s number) triggers a xe2x80x9ctermination attempt triggerxe2x80x9d or TAT. In response to the TAT, SSP 104 issues query 2, shown in FIG. 1a. Query 2 is a message that goes up to SCP 107 via STP 106 asking for directions as to how the call should be terminated. The query includes the following information: the subscriber""s telephone number (in the called party field), the calling party""s telephone number (in the calling party field), the calling party""s presentation restriction indicator (also in the calling party field), and, optionally, the trigger criteria type (indicating the service for which the query is intended).
SCP 107 checks the presentation indicator in the calling party field of the query received as a result of the termination attempt trigger. If presentation of the caller""s number is not restricted, i.e., if the caller""s number is public, SCP 107 sends back a response (response 3 in FIG. 1a) instructing SSP 104 to terminate the call, and to supply the caller""s telephone number (and, if the subscriber has subscribed to a higher level of service such as caller ID deluxe, the caller""s name and telephone number). In that case, SSP 104 terminates the call (call 1xe2x80x2 in FIG. 1a), i.e., completes the call, supplying the subscriber with the caller""s number (and possibly also with the caller""s name). If the caller""s name is to be supplied to the customer, SSP 104 launches another query, a TR1188 CNAM query to the SCP, to obtain the caller""s name from either database 107a or another database on the system that contains the names corresponding to the telephone numbers.
The prior art system of FIG. 1a asks the calling party to record his or her name whenever the calling party number is private or unknown. In this prior art system, if the caller""s number is private or unknown, SCP 107 enters the subscriber""s number in the calling party field in response 3 and directs SSP 104 to forward the call to SN 109 (call 1xe2x80x3 in FIG. 1a). When SN 109 answers the call, it asks the calling party to record his or her name. If the calling party responds by recording his or her name, SN 109 then calls the subscriber (call 4 in FIG. 1a), using the subscriber""s telephone number (that had been stored in the calling party field).
The TAT provisioned on the subscriber""s line at SSP 104 triggers a second time, sending a query (query 5) up to SCP 107 through STP 106. SCP 107 recognizes that this call originated with a service node, SN 109, and sends a response (response 6 in FIG. 1a) authorizing termination to the subscriber. SN 109 then plays a dialog to the subscriber, identifying the calling party by playing the calling party""s recorded name for the subscriber. If the subscriber chooses to accept the call, the call is put through (leg 4xe2x80x2 of call 4 in FIG. 1a). If the subscriber refuses to accept the call, the calling party is informed that his or her call was not accepted, and the call is disconnected.
This prior art system works irrespective of whether the calling party number is public (i.e., not private), private or unknown, but cannot take full advantage of the advanced intelligent network capabilities of the AIN system, because the calling party number is not preserved. Thus this prior art system does not allow the use of advanced intelligent network features such as call return or call trace.
The present invention is a system and method that allows calls to be terminated to a subscriber to a privacy screening service, even when the calling party is either private or unknown, and preserves the calling party number when the calling party number is known (whether the calling party number is public or private). The present invention is illustrated in FIGS. 2-3, which show the same basic AIN architecture as the network architecture of prior art systems of FIGS. 1-1a. FIG. 2 shows the operation of the present invention when the calling party is known (for both the case when the calling party number is private and the case when the calling party number is public). FIG. 3 shows the operation of the invention when the calling party number is unknown.
As shown in FIG. 2, when the calling party dials the subscriber""s number, the call is routed (as call 1 in FIG. 2) through the caller""s SSP (SSP 103), to the subscriber""s SSP, SSP 104. The call hits the subscriber""s TAT at SSP 104, triggering a query (query 2) in FIG. 2, which goes up to SCP 107 via STP 106, over SS7 links 110b and 110d (links 110b and 110d are identified in FIG. 1, but are not identified in FIGS. 2-3).
SCP 107 checks the calling party ID and presentation indicator in query 2, and determines whether the calling party is known and public, known and private, or unknown. In the present invention, if the calling party number is public and known, SCP 107 sends back a response authorizing termination to the subscriber (response 3 in FIG. 2). If the subscriber has subscribed to a service that provides the calling party""s name as well as the calling party""s telephone number, SSP 104 then launches a query (e.g., a TR-1188 query) to obtain calling name information from SCP 107 and its database 107a. Then SSP 104 terminates the call to the subscriber (call 1xe2x80x2 in FIG. 2), presenting the subscriber with the calling party""s number (and name, if the subscriber has subscribed to a service that provides the calling party""s name as well as the calling party""s number).
If the calling party number is private, SCP 107 re-writes the presentation indicator as xe2x80x9cpublicxe2x80x9d, i.e., redefines the presentation indicator in the presentation indicator field (i.e., the presentation_restricted_indicator portion of the calling party ID field in the query) as public. As shown in FIG. 2, SCP 107 responds to the TAT query from SSP 104 by directing SSP 104 to forward the call to SN 109, with the presentation indicator re-written as public. SSP 104 writes the subscriber""s number in the xe2x80x9cre-directing partyxe2x80x9d field, and forwards the call (call 1xe2x80x3 from SSP 104 to SN 109 in FIG. 2) to SN 109 at SN 109""s number via SSP 108. Thus, when the call is presented to SN 109, the call has the subscriber""s number in the xe2x80x9cre-directing partyxe2x80x9d field, and the original calling party""s number in the xe2x80x9ccalling partyxe2x80x9d field. Because SCP 107 has toggled the presentation indicator from xe2x80x9cprivatexe2x80x9d to xe2x80x9cpublicxe2x80x9d, SN 109 has access to the calling party number. SN 109 answers the call, and plays an announcement to the calling party, asking for his/her permission to present his/her number (and name) to the subscriber. If the calling party refuses to grant permission to present his/her number (and name) to the subscriber, the call is disconnected. If the calling party agrees to have his/her number (and name) presented, SN 109 dials a Customized Dialing Plan (CDP) code Y (e.g., *95), the 10-digit called party number, and the 10-digit calling party number (call 4 in FIG. 2).
The CDP code Y triggers a query at SSP 108, which launches an info_analyzed query to SCP 107 (query 4xe2x80x2 in FIG. 2), populating the xe2x80x9cAccess Codexe2x80x9d and xe2x80x9cCollected Digitsxe2x80x9d fields as follows:
Access Code=Y
Collected Digits=The remainder of the dialed digits, i.e., the 10-digit called party number followed by the 10-digit calling party number.
SCP 107 analyzes the dialed string and returns an analyze_route response (response 5) with:
CdPN=Subscriber""s number
CgPN=Calling party number
SSP 108 then dials the subscriber number (call 6 in FIG. 2). This call is routed through SSP 104, where it triggers a TAT query (query 7) from SSP 104 to SCP 107 with the following parameters:
CgPN=Calling party number
CdPN=Subscriber""s number
Charge Number=SN 109""s number, e.g., lead number for SN 109""s Multi Line Hunt Group (MLHG) number
SCP 107 recognizes the Charge Number as SN 109""s MLHG number, and authorizes SSP 104 to terminate the call (response 8). SSP 104 then presents the call to the subscriber (call 1xe2x80x2 in FIG. 2, with the presentation indicator set to xe2x80x9cpublicxe2x80x9d). SSP 104 obtains the calling party""s name by sending a CNAM TR-1188 query to SCP 107 (or to another SCP that responds to TR-1188 CNAM queries). As soon as the subscriber""s telephone rings, SN 109 can drop out of the route, with the call routed through SSPs 103, 104, 108 and 104 (again) and on to the subscriber.
FIG. 3 shows the operation of the present invention when the calling party is unknown. As above, the sequence starts when the calling party dials the subscriber""s number. The call is routed (as call 1 in FIG. 3) through the caller""s SSP, SSP 103, to the subscriber""s SSP, SSP 104. The call hits the subscriber""s TAT at SSP 104, triggering a query (query 2 in FIG. 3), which goes up to SCP 107 via STP 106, over SS7 links 110b and 110d. SCP 107 examines the presentation indicator in the calling party ID field in query 2, and determines that the calling party number is unknown.
In response 3 to query 2, SCP 107 then directs SSP 104 to route the call to SN 109 (call 1xe2x80x2 from SSP 104 to SN 109 in FIG. 3). The call arrives at SN 109 with the subscriber as the redirecting party, the calling party number in the calling party field, and the SN number in the called party field. When the call is presented to SN 109, SN 109 checks the calling party number, and determines that it is unknown. SN 109 then plays an announcement to the calling party, asking the calling party to record his or her name. If the calling party refuses to do so, the call is disconnected. If the calling party agrees to record his/her name, SN 109 dials the CDP code Y, the 10-digit called party number, and the 10-digit SN Multi Line Hunt Group number (call 4 in FIG. 3). The CDP code Y triggers a query at SSP 108, which sends an info_analyzed query (query 4xe2x80x2 in FIG. 3) to SCP 107, populating the xe2x80x9cAccess Codexe2x80x9d and xe2x80x9cCollected Digitsxe2x80x9d fields as follows:
Access Code=Y
Collected Digits=the remainder of the dialed digits, i.e., the 10 digit called party number and the 10-digit SN MLHG number.
SCP 107 analyzes the query and returns an analyze_route message (response 5) to SSP 108, which then calls the subscriber (call 6) with:
CdPN=subscriber""s number
CgPN=SN""s MLHG number.
This call triggers a TAT query (query 7) on the subscriber""s line at SSP 104. The query includes SN 109""s MLHG number as the calling party number, the subscriber""s number as the called party number, and SN 109""s MLHG number as the charge number. Since the charge number is the lead number for SN 109""s MLHG, SCP 107 sends SSP 104 an Authorize Termination message (response 8), authorizing termination of the call from SSP 104 to the subscriber. SSP 104 then executes a TR1188 query, which returns the privacy manager as the calling party name. SSP 104 then completes the call (call 1xe2x80x3). For subscribers to caller ID deluxe, the LCD display on the subscriber""s telephone will show, e.g., xe2x80x9cPrivacy Managerxe2x80x9d as the calling party.
SN 109 then plays an announcement to the subscriber, asking the subscriber whether he or she would like to accept or reject a call from the calling party, whose name is played for the subscriber as xe2x80x9crecorded name.xe2x80x9d The subscriber can then, e.g., accept the call by pressing 1, have a simple rejection played by pressing 2, have a xe2x80x9csales callxe2x80x9d rejection (xe2x80x9cwe do not accept sales calls, please remove this number from your caller listxe2x80x9d) played by pressing 3, or route the call to voicemail by pressing 4. If the subscriber accepts the call, SN 109 transfers control of the call to SSP 104, and drops out (although the call is still routed through SSP 108). If the subscriber rejects the call, SN 109 plays the announcement selected by the subscriber or routes the call to voicemail, and then the call is disconnected.
The present invention thus preserves the calling party number, such that the system can take full advantage of the capabilities of the advanced intelligent network, e.g., call return or call trace for all known calls, whether private or public.
It is an object of the present invention to offer a privacy screening service to subscribers that allows private calling parties to override their privacy, and that allows calls from unknown calling parties to be routed to the subscriber, and yet still allows the use of advanced intelligent network features.